A prospective study of patient assaults on nurses in a provincial psychiatric hospital in Canada.

A 27-month prospective study was conducted of patient assaults on nurses in a Canadian psychiatric hospital. Rates were low (4% of the patients committing an assault) and the injuries mostly trivial. Schizophrenics accounted for 43% of attacks, but when allowance was made for the disproportionate number of patients in the hospital with this diagnosis, individuals with mental retardation or dementia were approximately twice as likely to be assaultive as schizophrenics. Repeat assaulters (greater than 4 attacks) were more likely to be suffering from paranoid schizophrenia.